1. Field of the Invention
This invention relates generally to safety devices used on lift cords in pleated shades, venetian blinds and other window covering products and to window covering products having such safety devices.
2. Description of the Prior Art
Window shade assemblies and venetian blinds typically have window covering material or blind slats extending between a headrail and a bottomrail. In many of these products the window covering material or blind slats are raised and lowered by two or more lift cords or a cord loop extending from the headrail. In those products that have multiple lift cords the lift cords are connected at one end to the bottomrail and extend up through the window covering material or blind slats into the headrail. The lift cords then pass through a cord-locking device and out of the headrail such that an opposite end of the lift cords is accessible to an operator. Window shades and blinds of this type are typically raised by the operator pulling on the accessible portion of the lift cords and are lowered by releasing the lift cords. Because all lift cords must move in unison, the lift cords are typically tied together and the tied end is attached to a tassel. The lift cords often extend downward from the headrail to within a few feet of floor level.
In some window covering products the lift cords extend from the bottom of the window covering material into the headrail where they are wound around an axle. A cord loop is often provided around one end of the axle and extends from the headrail. An operator can raise and lower the window covering material by pulling the loop in a manner to cause the axle to turn in a desired direction. This type of prior art window covering is shown in FIG. 1.
The lift cords and cord loops of a window shade assembly present an attractive danger to infants or children who may play with the lift cords. There have been several instances in which children and infants have become entangled in the cords and accidentally hanged. These incidents prompted the Window Covering Manufacturers Association to develop standards for window coverings. These standards say that window coverings should not have accessible cord loops, or if such loops are present the loops must have a safety device that prevents entanglement.
One solution to this problem has been focused on a detachable connection of the lift cords. In U.S. Pat. No. 4,909,298 Langhart et al. discloses a breakaway tassel that is attached to multiple lift cords. The tassel is designed to enable the cords to separate into individual cords with free ends when subjected to a force. However, tests of a commercially available embodiment of the Langhart patent have shown that this product failed to detach in simulated entanglements. Then the manufacturer changed the product to the extent that the tassel often comes apart during normal use. When that happens people tie the cords together. Jelic in U.S. Pat. Nos. 5,553,650 and 5,577,543 provides a somewhat similar solution. Those patents disclose safety devices for a cord loop in which a blade cuts the loop when a force is applied to the device. None of the devices disclosed in these two patents were ever commercialized.
Another type of cord safety device is a shroud that extends from the headrail to a handle or tassel capturing all of the lift cords within the shroud. Jelic discloses a ribbon used as a cord shroud in U.S. Pat. No. 5,495,883 and a cord ladder used as a cord shroud in U.S. Pat. No. 5,613,540. When these safety devices are used the operator must pull the cords at their distal ends where the handle or tassel is located to raise and lower the window covering material. This can be very inconvenient for a long blind because the operator is required to lean over and/or walk several feet away from the window to fully raise the blind keeping the cord taut as he or she pulls the cord. The cord shrouds disclosed by Jelic are also not suitable for use on a cord loop and have never been commercialized. Consequently, there is a need for a cord shroud system in which an operator is able to pull the lift cords from a position intermediate the headrail and the distal ends of the cord. There is also a need for a cord shroud that can be used on a cord loop.
I provide a cord shroud for use in cooperation with a window shade assembly of the type having multiple lift cords or a cord loop extending from a headrail. I also provide a window covering of the type having lift cords in which the lift cords exit the headrail and pass through a cord capture device. The cord capture device has a fixed end and a moveable end. The fixed end need not be attached to the headrail. Instead the fixed end can be attached to the end of at least one lift cord or attached to the end of a release cord or other structure that is located at a point that is a selected distance from the headrail. In those embodiments where the fixed end is not attached to the end of the lifts cords, the fixed end will be at a point that is fixed relative to the headrail. The moveable end is moveable relative to the headrail, relative to all points on the lift cords and relative to the end of the release cord or other structure to which the fixed end is attached. The cord capture device or cord can be one of a number of structures having a plurality of apertures through which the lift cords pass.
In one embodiment the cord shroud has two elongated flexible ribbons, each ribbon having a plurality of apertures sized to permit the lift cords to pass through the apertures. The first end of one ribbon is connected to the headrail, to the handle of a release cord or to a tube extending from the headrail. I also provide a gripper attached to the second end of the first ribbon and attached to the first end of the second ribbon. The second end of the second ribbon can be attached to a tassel or a weight that is connected to the end of the lift cords or to the lowest portion of a cord loop. The gripper has a passageway through which the lift cords or the cord loop pass and is constructed such that the lift cords can pass freely through the passageway when the gripper is in a relaxed condition. The gripper will either allow the user to grip the lift cords while holding the gripper or the gripper itself will grip a portion of the lift cords that is in the passageway. Gripping may be accomplished through a spring-actuated plunger or when a force is applied to the gripper. If desired, an elastic retracting cord can be provided to return the gripper to its original position after each pull. Then the first ribbon is not required. When an operator wishes to raise a window covering he or she preferably squeezes the gripper and pulls the lift cords a comfortable distance. To continue raising the blind the operator slides the gripper up the lift cords toward the headrail without squeezing the gripper, then squeezes the gripper and pulls again. This process is repeated until the blind has been raised a desired amount. A cord lock or axle lock in the headrail locks the lift cords in place when the operator stops pulling the cords. Any conventional cord lock can be used. However, I prefer to provide a cord lock that automatically locks unless released by a mechanical linkage that is operated by a release. A shroud may be provided between the headrail and the release handle at the end of the release linkage. In this embodiment the first ribbon extends from the handle to the gripper.
I prefer that the gripper be a hollow ellipsoid or elliptical strap with a hole at each end through which the lift cords pass. The ellipsoid is made of a flexible material such as rubber. I also prefer to provide a finger loop on the gripper. Alternatively, the gripper may have a cam lock, which is closed to grip the cords and opened to allow free passage of the cords through the gripper.
The ribbons can be a strip of any suitable material including fabric, plastic, paper or even a cord. The ribbon material may be selected to match the window covering material. The apertures could be holes through the ribbon or provided by loops or rings attached to the ribbon or cord. I prefer to accordion pleat the ribbon. A fabric, paper or plastic ribbon may also be pleated such that each pleat terminates in a tab and the apertures are provided through the tabs. Yet, another alternative is to use a cord ladder for the ribbon. Still another alternative is a single cord having spaced-apart loops through which the lift cords are routed. Yet, another alternative is to use a coiled cord similar to the cords used to connect a telephone receiver to the main unit.
Other objects and advantages of the invention will become apparent from a description of certain present preferred embodiments thereof shown in the drawings.